Circuit-controller



C. T. EVANS AND R. B. HUNTER. CIRCUIT CONTROLLER.

APPLICATION FILED AUG-Z7. 1915.

1,379,971. I V Patented May31,1921.

mm W UNITED STATES PATENT OFFICE.

CLARENCE '1. EVANS AND RICHARD 1B. HUNTER, OF MILWAUKEE, WISCONSIN, ASSIGNORS TO THE CUTLER-HAMMER MFG. 00., O1 MILWAUKEE, WISCON-- SIN, A CORPORATION OF WISCONSIN.

CIRCUIT-CONTROLLER.

Specification of Letters Patent. Patented May 31, 1921.

Application filed August 27, 1915. Serial No. 47,636.

T 0 all whom it may concern United. States, residing at Milwaukee, in the county of Milwaukee and State of Wiscon-' sin, have invented new and useful Improvements in Circuit-Controllers, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

This, invention relates to improvements rotective circuit controllers.

ne of the objects of the invention is to provide improved means for interrupting the controlled circuit upon the occurrence of overloads and for necessitating a manual operation as a pre-requisite to reclosure of said circuit.

A further object is to provide improved means for interrupting the controlled circuit upon failure of voltage and for necessitating a manual operation as a pre-requisite to reclosure of said circuit.

A still further object is to provide improved means functioning as stated to interrupt the controlled circuit upon the occurrence of either an overload or failure of voltage and to insure against reclosure of circuit thereafter except by-a special operation for that purpose.

Other objects and advantages will hereinafter appear.

The accompanying drawings illustrate certain embodiments of the invention and the same will now be described, it being understood that the invention may be embodied in other forms falling within the scope of the appended claims.

In the drawing,

Figure 1 shows diagrammatically a controller for electric motors; and,

Fig. 2 shows diagrammatically a modification of the controller shown in Fig. 1.

Referring to Fig. 1, the same shows a compound motor 1 having an armature A, a series field F and a shunt field f, together with a drum type controller 2 for starting and accelerating the motor through the medium of an armature resistance R and circuit breaking means including an electromagnetic switch 3 and an overload relay More specifically describing the circuit breaking means theswitch 3 thereof 1s provided with a pivoted contact arm 5 having an operating magnet 6 anda restraining or lockout magnet 7 acting upon an extension 8 of said arm. The magnets 6 and 7 acting upon opposite sides of the pivot of contact arm 5 oppose one another and said magnets are so designed that when said arm is in the position illustrated energi'zation of the magnet 7; will hold the same against attraction by the magnet 6, whereas magnet 6 after attracting said arm will hold the same against attraction by the magnet 7. The magnet 6 is directly connected across the sup-ply lines L and L through the overload relay L and is accordingly subject to deenergization' either upon failure of voltage or upon response of said overloadrelay. The magnet 7, on the other hand, is connected across the supply lines through the controller 2 to be included in circuit upon completion of the motor circuit by said controller and to remain in circuit until the controller is moved to interrupt the motor circuit.

It will thus be apparent that with the controlling elements in the positions illustrated closure of line switch S will complete the circuit of magnet 6, which will then attract arm 5 to close switch 3, the magnet 7 at this time being disconnected from circuit. Thereupon the motor may be started by operation of the controller, 2

rent by response of the overload relay 4.

Thus the motor circuit is automatically opened to protect the motor but without interruption of the circuit of magnet 7. Accordingly even though the magnet 6 be again energized by restoration of voltage or by reclosure of overload relay 4, 1t will be ineffective to reclose switch 3 due to the lockout action of magnet 7 Thus, to effect resetting of the switch 3 it is necessary to move the controller to off position to deenergize magnet 7 and likewise to interrupt the motor circuit so that the motor is positively insured against restarting without reparent that the magnet 7 might be so connected with the controller 2 as to be ener gized and deenergized in any desired position thereof but ordinarily it would be preferable to connect the same as illustrated.

While the circuit connections are simple and obvious the same will now be briefly described. The motor circuit is traceable from line L to contact 2* of controller 2, through segments 2 and 2 to contact 2, thence through the resistance R by conductor 10 through the motor armature and series field, by conductor 11 through the winding of overload relay 4, by conductor 12 through switch 3 when closed to line L. The shunt field circuit of the motor is traceable from contact 2 by conductor 13 through said field to conductor 11 and thence as already traced 'to line L. Resistance R is adapted to be short-circuited in steps by progressive engagement of controller segments 2*, 2 and 2 with contacts 2, 2 and 2 respectively. lhe

circuit of magnet 7 is traceable from controller contact 2 by conductors 13 and 14L through said magnet, by conductors 15 and 16 to line L, whlle the circuit of magnet 6 is traceable directly from line L by conductor 17 through overload relay 4, by conductor 18 through said magnet to conductor 16 and thence to line L.

Referring now to Fig. 2 the same shows a controller like that of Fig. 1 in all respects except that the magnet 7 of the circuit-breaker is included in series-with the motor while the circuit-breaker switch 3 is provided with a high resistance R con- ,r-ilected in shunt thereto. In consequence the 40 controller will function precisely as the controller above described except that instead of completely interrupting the motor circuit upon release of switch 3 it will protect the I same by including in circuit therewith the high resistance R This resistance will reduce the flow of current in the motor circuit to a value insuring against injury of.the

motor while at the same time permitting a sufiicient flow of current to render the magnet 7 effective to lock out the switch 3? What we claim as new and desire to secure by Letters Patent is: i

1. A circuit controller including a protective switch, a winding for'setting and holding said switch subject to release upon failure of voltage, means controlling said winding to also efi'ect release of said switch upon the occurrence of overloads and a second winding for said switch to oppose resetting thereof when released upon either failure of. voltage or an overload. I

2. A circuit controller, including a protective switch, a winding for setting and holding Said switch subject to release upon failure of voltage, means controlling said winding to also efi'ect release of said switch upon thereof when released veither upon failure of volta e or an overload, and means jointly controlling atwill the protected circuit and the circuit of said second winding.

3. A circuit controller including a protective switch, a winding for setting and holding said switch subject to release upon failure of voltage, an overload relay in circuit with said winding, a lockout winding for said switch, said lockout winding being controllable at will and positively predominating said operating winding 1n the released position of said switch but being subordinate to said operating winding in the set position of said switch.

4. A circuit controller including a pro-- tective switch having a contact arm pivoted intermediate of its extremities, a winding acting upon oneend of said switch arm to set and hold the same, a second winding acting upon the other end of said switch arm to restrain the same against operation said windings being proportioned to positively predominate one another according to the position of said arm.

5. A circuit controller including a protecintermediate its extremities, a winding acting upon one end of said switch arm to set and hold the same, a second winding acting upon the other end of said switch arm to restrain the same against operation, said windin s bein magnetically independent of each ot or an being proportioned to positively predominate one another according to the position of said arm.

7. A circuit controller including a protective switch having a cont'actarm ivoted intermediate its extremities, a win ing connected across the protected circuit and acting upon one end of said switch arm to set and hold the same, a second winding acting upon the other end of said switch arm to restrain the same against operation, said windings being proportioned to positively predominate one another according tothe position of said arm.

8. A circuit controller including a protective switch having acontact arm ivoted intermediate its extremities, a win in connected across the protected circuit and acting upon one end of said switch arm.to

set and hold the same, a second winding acting upon the other end of said switch arm to restrain the same against operation, said windings being proportioned to positively predominate one another according to the position of said arm, said former winding being subject to deie'nergization upon, failure of voltage in said protected circuit, and means for effecting deenergizatipn of said winding upon the occurrence of anoverloadin said circuit.

9. A circuit controller including a protective switch having a contact arm pivoted intermediate its extremities, a winding connected across the protected circuit and acting upon one end of said switch arm to set and hold the same, a second winding acting upon the other end of said switch arm to restrain the same against operation, said windings being proportioned to positively predominate one another according to the position of said arm, means for effecting deenergization of said former winding upon the occurrence of an overload in the protected circuit and manual means for controlling the, energization of said second mentioned winding.

In witness whereof, we have each hereunto subscrlbed our name.

CLARENCE 'r. EVANS. RICHARD B. HUNTER, 7 

